@AlekseyB malloc, realloc and free()are actually C not C++.
In C++ one usually uses new and delete.
Since Qt is a C++ framework you use C++ language - so use new/delete. There is no need for Qt to reinvent the wheel.

As I understand operators new and delete are used to individual objects. But I need allocation memory for array of objects. For example, to allocate 1000 elements of type char. Is operators new and delete is applicable for this problem?

As I understand operators new and delete are used to individual objects. But I need allocation memory for array of objects. For example, to allocate 1000 elements of type char. Is operators new and delete is applicable for this problem?

Usually it's nowadays recommended that manual low-level memory management is avoided in C++ as much as possible. You may want to use QVector instead: "reserve(size) explicitly preallocates memory for size items". Or QByteArray. See http://doc.qt.io/qt-5/containers.html. I don't know your background or real needs, but if you for example come from C and embedded systems background and are now trying desktop applications it's recommended to go higher level than you have used to, leaving []-arrays and char* behind. Ignore me if you already know what you need.